In recent years, three-dimensional (3D) display has become one of the main trends in the display field. The basic principle of 3D display is based on the fact the left eye and right eye of a human receive different images respectively. Two eyes of the human being have an interval of about 65 mm therebetween. Due to the positional difference, the left eye and the right eye will see different two-dimensional (2D) images; subsequently, the brain performs superimposition and regeneration on information of different 2D images received by the left eye and the right eye, and hence an image with front-rear, up-down, left-right and far-near 3D direction effect can be obtained.
The 3D display technology can be embodied with the help of special glasses. The wearing of the special glasses will reduce the application scope of 3D display and the use comfort. In addition, glasses-free 3D display technology has gradually become mature. A glasses-free (naked-eye) 3D display device comprises a display panel and a grating. The grating comprises a plurality of grating units. The grating is disposed in front of the display panel by a certain means. An image displayed by the display panel is divided into a left-eye image and a right-eye image by the grating. Thus, different visual images can be viewed by two eyes of the human being, and hence 3D effect can be obtained.